1. Field of the Invention
The present invention relates in a first aspect to a formwork element for bounding a trench wall section of a trench wall.
In another aspect the invention relates to a formwork part which is in particular adapted to form a formwork element according to the invention.
Finally, the invention relates to a method for producing a trench wall in the ground, in which trench wall sections lying next to each other are formed in the ground by means of a trench wall device, in particular by a trench wall cutter, wherein at least one trench wall section is bounded by an introduced formwork element.
2. Description of Related Art Including Information Disclosed Under 37 CFR §§1.97 and 1.98
A generic formwork element and a generic method are known for instance from DE 90 01 679 U1.
It is known to employ formwork elements, such as e.g. stop-end tubes made of steel, in order to limit sections of a trench wall that are to be produced of concrete. The width or diameter of such formwork elements that are lowered into the construction joint prior to concreting corresponds to the thickness of the trench wall. Following the setting of the concrete these formwork elements have to be removed, for example by being drawn vertically upwards out of the construction joint by means of hydraulic devices. As it proves to be quite difficult to determine the point of setting of the concrete that is most favourable for withdrawal this frequently leads to situations in which the concrete has set either to an insufficient degree or else has hardened too much. In the first case parts of the freshly concreted trench wall cave in during withdrawal of the formwork elements and in the second case withdrawal of the formwork elements is considerably difficult and, in some cases, even impossible.
In order to avoid these difficulties prefabricated elements are also used in the prior art for bounding trench wall sections which remain in the ground after concreting the respective trench wall sections. Such prefabricated elements can be made of steel or concrete for example. In larger trench wall depths, however, such components are extremely bulky due to their weight. In addition, in the case of formwork elements made of concrete these must have hardened very well so as to avoid damage, which results in a very long storage time. Due to the sensitivity of concrete in regard to tensile loads are concerned, such formwork components of concrete typically need to have hardened for approximately four weeks.